Elastic bulkhead.



W. HOVGAARD.

ELASTIC BULKHEAD.

APPLxcATxoN FILED MAR. 1. 1915.

1 1 64, 8 1 4. Patented Dec. 21, 1915.

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UNITED STATES PATENT OFFICE.

WILLIAM HOVGAARD, 0F BROOKLINE, MASSACHUSETTS.

ELASTIC BULKHEAD.

Application led March 1, 1915.

To all Lo/tom t may concern:

Be it known that I, lViLLmM Hovesann, a subject of King Christian X of Denmark, residing at Brookline, in the county of Norfolk and State of Massachusetts, have invented new and useful Improvements in Elastic Bulkheads, of which the following is a specification.

This invention relates to improvements in curved so-called elastic7 bulkheads.

The object of the invention is to provide a watertight bulkhead, which is designed and constructed as a protection to the vital parts of vessels from under water explosions such as may be produced by mines or torpedoes and to further resist iiying missiles or fragments. Said bulkhead is also adapted to maintain the vessel afloat even though the outer shell or hull of the vessel has been injured or rendered useless.

Heretofore it has been customary to construct protective bulkheads of one or more plane layers of very heavy plating supported by relatively very light and weak stiffeners. Such bulkheads offer but very small resistance to the enormous gas pressures of under water explosions. The flat plating will bend and crack, the stiffeners will yield readily at small pressures.

In this invention the plating constituting the protective bulkhead has been shaped in a series of corrugations, c'. e. a series of semicylindrical or more lightly curved sections secured together and supported by stiifeners at the sides of each of the curved sections, thus presenting a. curved concave surface against which the forces from the explosions, etc., will act, subjecting the plating to tension.

It is a well-known fact that a cylindrical or curved shell is capable of withstanding a far greater pressure than is a rectangular or flat sided shell, owing to the fact that the stresses are more evenly and uniformly distributed in the metal of the curved shell. By combining the curved sections of plating with a series of very deep and strong stiffeners arranged at the sides of said curved sections an exceptionally strong bulkhead will be provided. The thickness of the plating may be made very much less than that necessary for the plane plating for bulkheads of equal strength as far as gas pressures are concerned, although in order to yresist; the impact of fragments and projec- Specicaton of Letters Patent.

Patented Dec. 21, 1915.

Serial No. 11,182.

tiles, it is well in vessels of the battleship class to use heavy plating of a strong and tough material.

The invention consists in the combination and arrangement of parts setforth in the following specification and particularly pointed out in the claims.

Referring to the drawings: Figure 1 is a partial transverse section through the hull of a vessel illustrating a bulkhead embodying my invention. Fig. 2 is a section taken on the line 2-2 of Fig. 1. Fig. 3 is a section similar to Fig. 2 illustrating a modiiied form of my invention.

Like numerals refer to like parts throughout the several views of the drawings.

In the drawings, 5 represents the hull of a vessel.

6 is the protective deck and 7 the platform deck of said vessel.

8 is an elastic bulkhead which is arranged at a certain distance from the side of the vessel and may extend entirely around the vessel, or if desired, around the vital parts of the vessel. The outer hull presents a smooth surface to the water in order to prevent undue resistance, but is not necessarily of sufficient strength to withstand abnormal forces, such as from the explosions of mines or torpedoes, while the inner hull or bulkhead 8 is constructed for the purpose of resisting such forces. The space intervening between the bulkhead 8 and the side of the hull may, if desired, be utilized as fuel bunkers or storage compartments.

The bulkhead 8 embodies in its construction a corrugated wall of plating 9 within which is arranged a series of supports or stiffeners 10, which stiifeners are disposed substantially at right angles to said wall and secured thereto. The preferred construction of the corrugated wall 9 consists of a series of large corrugations or arcuately formed upright sections 11 which curve inward relatively to the outer faces 12 of the stifleners 10, said large corrugations alternating with a series of relatively smaller corrugations 13 which are reversely curved relatively to said large corrugations and within which said stiffeners 10 are secured.

The sti ileners 10 preferably consist of upright, parallelly disposed plates 14 constituting the webs which are fixed or secured at their upper and' lower ends to the hull structure, such as the decks 6 and 7 and the inner l bottom 15, said plates being secured to said decks and to the inner bottom by means of angle-bars 16, 16 which are riveted respectively to said decks and said plates. Stiftening bars 17, 17 are arranged transversely of the plates 14 to prevent buckling'thereof. The upper and lower edges of the corrugated wall 9 are fixed or secured to the hull structure preferably by double bounding bars or angles 18, 18 which are bent to conform to the shape of said corrugated wall and secured tov said opposite sides of said Wall. The corrugated wall 9 is also secured to the plates 14 preferably by means of angle-bars 19 which are secured to the opposite outer edges of said plates. The flanges 21 of said angle-bars 19 are curved t0 conform to the smaller corrugations 13 of said plating, thus providing a complete and elastic support for the plating. f l

To secure absolute Watertightness in case the elastic bulkhead is strained or otherwise damaged, an inner plane wall 22 is fitted, when necessary, to the inner edges of the stiffeners, providing also longitudinal strength for the vessel as a who-le, and ,preventing lateral deflection of the Webs of the stiifeners relative to each other. The wall 22 is secured to the plates 14 preferably by anglebars 23 in a similarmanner to that in which the corrugated wall is secured to the outer edges of said supports. Said inner Wall is also secured preferably by double bounding bars 24 to the hull structure. The double walls of the bulkhead combine to produce a cofferdam which may be used as a. storage chamber, if desired, thus saving considerable space inthe vessel.

In Fig.; 3 'Ik have illustrated another method of constructing the corrugated wall.

ln this form the corrugations may consist' of a series of substantially semicylindrical yplates 25 interposed between the Web plates 14 of the stiffeners 10. These plates are secured at opposite sides to the web 'plates 14 preferably by rivets 26, while to reinforce the inner edges ofthe stiifenersthe opposite edges of the curved plates are turned inward as at 27 and a face plate 28 extends from the inturned edge of one to the inturned edge of the adjacent plate. rlhe plates 25 are adapted to curve inward rela- Y tively to the outer edges of the plates 14 -ing may' be made and vice versa.

thus presenting their concave faces to the forces to be resisted. rlhe inner edges ofv formed the arc may more nearly approachV a straight line. When the plating is merely to resist pressure of gas or water the arc of f said sections may more nearly approach a senncircle and the thickness of the metal may be less than in the armored structure.

It should therefore be understood that this invention is not to be limited to any par7 ticular arc or form of corrugation, but that saidform may be Varied according to the requirements of the vessel to which the bulkhead is to be attached.

Having thus described my invention What cure is n 1 claim and desire by Letters Patent to sei 1. A bulkhead embodying in its construe# l tion a series of fixed supports, a wall of substantially planeplating secured to the inner faces of said ser1es of supports, and asecond wall of plating secured to the outer edges yof said series of supports, said second Wall being curved inwardly intermediate vsaid supports. f l

2. A bulkhead embodying infits construction a wall having a series of large corrugations andy a series of relatively smaller corrugations alternating with said larger corrugations, said large' and vsmall corrugations being reversely 'curved relatively to each other, and a series of fixed supports disposed substantially at right angles to said wall and secured thereto within said smaller corrugations.v v

3. LA bulkhead `embodying in itsconstruction aseries of upright parallelly disposed plates, each permanently fixed at its upper and lower ends, an inner wall `of metal secured to the inner 'edges of said upright their upper and lower ends, angle barsse-j cured to the inner and outer opposite edges of said plates, the flanges of theV angle bars at the outer edges of said plates being curved from the outer edges ofsaid plates inwardly relatively to said series, an outer wall -of plating curved to conform to the curved flanges of said angle bars and secured thereto, said plating being also curved intermedi-y ate said angle bars in a reverse direction to y the curved portions vsecured to said flanges,

and a second wall of plating extending transversely of and secured to the inner edges of said upright plates, saidv second wall being adapted to prevent deflection of saidplates laterally relativelyto each other. 5. The combination vwith the hull of a vessel of a corrugated Wall disposed at a distance from the side of said hull and se* In testimony whereof I have hereunto set cured to the 11u11 structure, a substantially my hand in presence of two subscribing witlat wall arranged at :i distance from said nesses.

corrugated wall, said flat wall beingr also WILLIAM HOVGAARD. Qeoured to said hull structure, and a series Witnesses:

of stieners secured between and to Said SYDNEY E. TAFT,

walls and also secured to said hull structure. ANMB J. DAILEY.

Copies of this patent may be obtained for ve cents each, by addressing the Commissioner of Patents, Washington, D. C. 

